tvl-depot/absl/flags/marshalling.h

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Export of internal Abseil changes. -- 78293ba4eb4981991ae7e6edd25eb9245fcd7515 by Andy Soffer <asoffer@google.com>: internal changes PiperOrigin-RevId: 247073879 -- 7bd97e3aad0c3012b89a39392a6ad3f254e9f3c3 by Derek Mauro <dmauro@google.com>: Release commandline flags PiperOrigin-RevId: 247065920 -- 2a991849fd7b140a43b073076d194b61533fd199 by Tom Manshreck <shreck@google.com>: Add documentation for built-in usage flags PiperOrigin-RevId: 247058863 -- 14157b0de45841706bbd631284191fd94c313db9 by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 247058292 -- ed67e0a80468596e30540b367727a250fa415b68 by Abseil Team <absl-team@google.com>: Internal Change. PiperOrigin-RevId: 246828655 -- e1bc8c2aa3f90b3d56c55c5b7244e718c919265d by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 246822325 -- 907a68f287199f749cb9bdb48571b50bc34731e1 by Eric Fiselier <ericwf@google.com>: Accept vector<bool>::reference in StrCat and friends. Converting vector<bool>::reference to alphanum requires two user defined conversions, which isn't allowed. In order to accept this, we need a special constructor that is only enabled for the bool proxy types. PiperOrigin-RevId: 246626732 -- fe4295fa95cc65dee8c881ba12dd8f516e68c40d by Abseil Team <absl-team@google.com>: Clarify the proper way to define AbslHashValue, and fix confusing indentation. PiperOrigin-RevId: 246406528 -- d7174681a72d4a25c8fd2b4d9f515a0763eff87c by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 246358214 -- a7fdc19683cf1a5885e9e1af52fcdb2db1eda53b by Abseil Team <absl-team@google.com>: Fix sample template instantiation. PiperOrigin-RevId: 246354617 -- 29a23c6835f872948d09b24d890385bf195bc995 by Abseil Team <absl-team@google.com>: Fix incorrectly copy-pasted static_assert in absl::optional::value_or The static_assert for a move-constructible type previously said the type must be copy-constructible. PiperOrigin-RevId: 246313827 -- 41884d5872d4ea2c67875b00144b8c8a5859a295 by Greg Falcon <gfalcon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 245418790 -- 7f90a7f94cdd5e21232c749efe952a750b5c43a2 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 245412658 -- 730a329cf047d54b46971fce1781edd857208c2a by Greg Falcon <gfalcon@google.com>: internal change PiperOrigin-RevId: 245293234 -- cf0216be6338200cbb18167d3f3b2e98e372be77 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 245288164 GitOrigin-RevId: 78293ba4eb4981991ae7e6edd25eb9245fcd7515 Change-Id: I5ea9a852c36c722bae2d6be65fb7f72473d94ab6
2019-05-07 21:56:42 +02:00
//
// Copyright 2019 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// -----------------------------------------------------------------------------
// File: marshalling.h
// -----------------------------------------------------------------------------
//
// This header file defines the API for extending Abseil flag support to
// custom types, and defines the set of overloads for fundamental types.
//
// Out of the box, the Abseil flags library supports the following types:
//
// * `bool`
// * `int16_t`
// * `uint16_t`
// * `int32_t`
// * `uint32_t`
// * `int64_t`
// * `uint64_t`
// * `float`
// * `double`
// * `std::string`
// * `std::vector<std::string>`
//
// Note that support for integral types is implemented using overloads for
// variable-width fundamental types (`short`, `int`, `long`, etc.). However,
// you should prefer the fixed-width integral types (`int32_t`, `uint64_t`,
// etc.) we've noted above within flag definitions.
//
// In addition, several Abseil libraries provide their own custom support for
// Abseil flags.
//
// The Abseil time library provides the following support for civil time values:
//
// * `absl::CivilSecond`
// * `absl::CivilMinute`
// * `absl::CivilHour`
// * `absl::CivilDay`
// * `absl::CivilMonth`
// * `absl::CivilYear`
//
// and also provides support for the following absolute time values:
//
// * `absl::Duration`
// * `absl::Time`
//
// Additional support for Abseil types will be noted here as it is added.
//
// You can also provide your own custom flags by adding overloads for
// `AbslParseFlag()` and `AbslUnparseFlag()` to your type definitions. (See
// below.)
//
// -----------------------------------------------------------------------------
// Adding Type Support for Abseil Flags
// -----------------------------------------------------------------------------
//
// To add support for your user-defined type, add overloads of `AbslParseFlag()`
// and `AbslUnparseFlag()` as free (non-member) functions to your type. If `T`
// is a class type, these functions can be friend function definitions. These
// overloads must be added to the same namespace where the type is defined, so
// that they can be discovered by Argument-Dependent Lookup (ADL).
//
// Example:
//
// namespace foo {
//
// enum OutputMode { kPlainText, kHtml };
//
// // AbslParseFlag converts from a string to OutputMode.
// // Must be in same namespace as OutputMode.
//
// // Parses an OutputMode from the command line flag value `text. Returns
// // `true` and sets `*mode` on success; returns `false` and sets `*error`
// // on failure.
// bool AbslParseFlag(absl::string_view text,
// OutputMode* mode,
// std::string* error) {
// if (text == "plaintext") {
// *mode = kPlainText;
// return true;
// }
// if (text == "html") {
// *mode = kHtml;
// return true;
// }
// *error = "unknown value for enumeration";
// return false;
// }
//
// // AbslUnparseFlag converts from an OutputMode to a string.
// // Must be in same namespace as OutputMode.
//
// // Returns a textual flag value corresponding to the OutputMode `mode`.
// std::string AbslUnparseFlag(OutputMode mode) {
// switch (mode) {
// case kPlainText: return "plaintext";
// case kHtml: return "html";
Export of internal Abseil changes. -- 78293ba4eb4981991ae7e6edd25eb9245fcd7515 by Andy Soffer <asoffer@google.com>: internal changes PiperOrigin-RevId: 247073879 -- 7bd97e3aad0c3012b89a39392a6ad3f254e9f3c3 by Derek Mauro <dmauro@google.com>: Release commandline flags PiperOrigin-RevId: 247065920 -- 2a991849fd7b140a43b073076d194b61533fd199 by Tom Manshreck <shreck@google.com>: Add documentation for built-in usage flags PiperOrigin-RevId: 247058863 -- 14157b0de45841706bbd631284191fd94c313db9 by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 247058292 -- ed67e0a80468596e30540b367727a250fa415b68 by Abseil Team <absl-team@google.com>: Internal Change. PiperOrigin-RevId: 246828655 -- e1bc8c2aa3f90b3d56c55c5b7244e718c919265d by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 246822325 -- 907a68f287199f749cb9bdb48571b50bc34731e1 by Eric Fiselier <ericwf@google.com>: Accept vector<bool>::reference in StrCat and friends. Converting vector<bool>::reference to alphanum requires two user defined conversions, which isn't allowed. In order to accept this, we need a special constructor that is only enabled for the bool proxy types. PiperOrigin-RevId: 246626732 -- fe4295fa95cc65dee8c881ba12dd8f516e68c40d by Abseil Team <absl-team@google.com>: Clarify the proper way to define AbslHashValue, and fix confusing indentation. PiperOrigin-RevId: 246406528 -- d7174681a72d4a25c8fd2b4d9f515a0763eff87c by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 246358214 -- a7fdc19683cf1a5885e9e1af52fcdb2db1eda53b by Abseil Team <absl-team@google.com>: Fix sample template instantiation. PiperOrigin-RevId: 246354617 -- 29a23c6835f872948d09b24d890385bf195bc995 by Abseil Team <absl-team@google.com>: Fix incorrectly copy-pasted static_assert in absl::optional::value_or The static_assert for a move-constructible type previously said the type must be copy-constructible. PiperOrigin-RevId: 246313827 -- 41884d5872d4ea2c67875b00144b8c8a5859a295 by Greg Falcon <gfalcon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 245418790 -- 7f90a7f94cdd5e21232c749efe952a750b5c43a2 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 245412658 -- 730a329cf047d54b46971fce1781edd857208c2a by Greg Falcon <gfalcon@google.com>: internal change PiperOrigin-RevId: 245293234 -- cf0216be6338200cbb18167d3f3b2e98e372be77 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 245288164 GitOrigin-RevId: 78293ba4eb4981991ae7e6edd25eb9245fcd7515 Change-Id: I5ea9a852c36c722bae2d6be65fb7f72473d94ab6
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// }
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// return absl::StrCat(mode);
Export of internal Abseil changes. -- 78293ba4eb4981991ae7e6edd25eb9245fcd7515 by Andy Soffer <asoffer@google.com>: internal changes PiperOrigin-RevId: 247073879 -- 7bd97e3aad0c3012b89a39392a6ad3f254e9f3c3 by Derek Mauro <dmauro@google.com>: Release commandline flags PiperOrigin-RevId: 247065920 -- 2a991849fd7b140a43b073076d194b61533fd199 by Tom Manshreck <shreck@google.com>: Add documentation for built-in usage flags PiperOrigin-RevId: 247058863 -- 14157b0de45841706bbd631284191fd94c313db9 by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 247058292 -- ed67e0a80468596e30540b367727a250fa415b68 by Abseil Team <absl-team@google.com>: Internal Change. PiperOrigin-RevId: 246828655 -- e1bc8c2aa3f90b3d56c55c5b7244e718c919265d by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 246822325 -- 907a68f287199f749cb9bdb48571b50bc34731e1 by Eric Fiselier <ericwf@google.com>: Accept vector<bool>::reference in StrCat and friends. Converting vector<bool>::reference to alphanum requires two user defined conversions, which isn't allowed. In order to accept this, we need a special constructor that is only enabled for the bool proxy types. PiperOrigin-RevId: 246626732 -- fe4295fa95cc65dee8c881ba12dd8f516e68c40d by Abseil Team <absl-team@google.com>: Clarify the proper way to define AbslHashValue, and fix confusing indentation. PiperOrigin-RevId: 246406528 -- d7174681a72d4a25c8fd2b4d9f515a0763eff87c by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 246358214 -- a7fdc19683cf1a5885e9e1af52fcdb2db1eda53b by Abseil Team <absl-team@google.com>: Fix sample template instantiation. PiperOrigin-RevId: 246354617 -- 29a23c6835f872948d09b24d890385bf195bc995 by Abseil Team <absl-team@google.com>: Fix incorrectly copy-pasted static_assert in absl::optional::value_or The static_assert for a move-constructible type previously said the type must be copy-constructible. PiperOrigin-RevId: 246313827 -- 41884d5872d4ea2c67875b00144b8c8a5859a295 by Greg Falcon <gfalcon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 245418790 -- 7f90a7f94cdd5e21232c749efe952a750b5c43a2 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 245412658 -- 730a329cf047d54b46971fce1781edd857208c2a by Greg Falcon <gfalcon@google.com>: internal change PiperOrigin-RevId: 245293234 -- cf0216be6338200cbb18167d3f3b2e98e372be77 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 245288164 GitOrigin-RevId: 78293ba4eb4981991ae7e6edd25eb9245fcd7515 Change-Id: I5ea9a852c36c722bae2d6be65fb7f72473d94ab6
2019-05-07 21:56:42 +02:00
// }
//
// Notice that neither `AbslParseFlag()` nor `AbslUnparseFlag()` are class
// members, but free functions. `AbslParseFlag/AbslUnparseFlag()` overloads
// for a type should only be declared in the same file and namespace as said
// type. The proper `AbslParseFlag/AbslUnparseFlag()` implementations for a
// given type will be discovered via Argument-Dependent Lookup (ADL).
//
// `AbslParseFlag()` may need, in turn, to parse simpler constituent types
// using `absl::ParseFlag()`. For example, a custom struct `MyFlagType`
// consisting of a `std::pair<int, std::string>` would add an `AbslParseFlag()`
// overload for its `MyFlagType` like so:
//
// Example:
//
// namespace my_flag_type {
//
// struct MyFlagType {
// std::pair<int, std::string> my_flag_data;
// };
//
// bool AbslParseFlag(absl::string_view text, MyFlagType* flag,
// std::string* err);
//
// std::string AbslUnparseFlag(const MyFlagType&);
//
// // Within the implementation, `AbslParseFlag()` will, in turn invoke
// // `absl::ParseFlag()` on its constituent `int` and `std::string` types
// // (which have built-in Abseil flag support.
//
// bool AbslParseFlag(absl::string_view text, MyFlagType* flag,
// std::string* err) {
// std::pair<absl::string_view, absl::string_view> tokens =
// absl::StrSplit(text, ',');
// if (!absl::ParseFlag(tokens.first, &flag->my_flag_data.first, err))
// return false;
// if (!absl::ParseFlag(tokens.second, &flag->my_flag_data.second, err))
// return false;
// return true;
// }
//
// // Similarly, for unparsing, we can simply invoke `absl::UnparseFlag()` on
// // the constituent types.
// std::string AbslUnparseFlag(const MyFlagType& flag) {
// return absl::StrCat(absl::UnparseFlag(flag.my_flag_data.first),
// ",",
// absl::UnparseFlag(flag.my_flag_data.second));
// }
#ifndef ABSL_FLAGS_MARSHALLING_H_
#define ABSL_FLAGS_MARSHALLING_H_
#include <string>
#include <vector>
#include "absl/strings/string_view.h"
namespace absl {
namespace flags_internal {
// Overloads of `AbslParseFlag()` and `AbslUnparseFlag()` for fundamental types.
bool AbslParseFlag(absl::string_view, bool*, std::string*);
bool AbslParseFlag(absl::string_view, short*, std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, unsigned short*, std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, int*, std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, unsigned int*, std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, long*, std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, unsigned long*, std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, long long*, std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, unsigned long long*,
std::string*); // NOLINT
bool AbslParseFlag(absl::string_view, float*, std::string*);
bool AbslParseFlag(absl::string_view, double*, std::string*);
bool AbslParseFlag(absl::string_view, std::string*, std::string*);
bool AbslParseFlag(absl::string_view, std::vector<std::string>*, std::string*);
template <typename T>
bool InvokeParseFlag(absl::string_view input, T* dst, std::string* err) {
// Comment on next line provides a good compiler error message if T
// does not have AbslParseFlag(absl::string_view, T*, std::string*).
Export of internal Abseil changes. -- 4a21ad4ffa957d28b770de8717289fab7410f567 by Gennadiy Rozental <rogeeff@google.com>: Internal cleanup PiperOrigin-RevId: 252366381 -- b6b0f25439549c54f1537a16625be1fecd3c7d8c by Xiaoyi Zhang <zhangxy@google.com>: Fix C4245 compiler warning of visual studio. This allows using abseil headers in code requiring strict warning settings. This is an import of https://github.com/abseil/abseil-cpp/pull/321. PiperOrigin-RevId: 252101240 -- 0543b7861b658a5a665298e1d868e29968ff7b27 by CJ Johnson <johnsoncj@google.com>: Adds new benchmarks for the constructors of InlinedVector PiperOrigin-RevId: 251905349 -- c65a08507917e9f8f6450b8beb235fe1426d7954 by CJ Johnson <johnsoncj@google.com>: Updates the InlinedVector BatchedBenchmark abstractions to 1) provide the index of the instance back to the prepare and test functions so that callers may perform extra work on local state with a unique per-instance ID and 2) reduce the number of manually written calls to BENCHMARK_TEMPLATE. PiperOrigin-RevId: 251895546 -- 99a1ae2d786b80096172f6e018711e15c0c750b9 by Samuel Benzaquen <sbenza@google.com>: Fix ambiguous construction problem in absl::variant<> to make in line with std::variant. ImaginaryFun is hiding duplicate objects instead of causing ambiguity. Add a second unique argument to make sure all overloads exist in the final overload set. PiperOrigin-RevId: 251860694 -- b54d0a12673be6ebb6e77e24a556ce9b758b3a7e by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 251739183 -- f51b115e0dc3fc9a9c9c20b33a1f27027a700d48 by Abseil Team <absl-team@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 251686812 -- 30e868049282dc6a6fc77d923ca7d2a5d35a1658 by Xiaoyi Zhang <zhangxy@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 251652119 GitOrigin-RevId: 4a21ad4ffa957d28b770de8717289fab7410f567 Change-Id: I7171cb613793fa90e0eb0143b65ec8264a2a84db
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return AbslParseFlag(input, dst, err); // Is T missing AbslParseFlag?
Export of internal Abseil changes. -- 78293ba4eb4981991ae7e6edd25eb9245fcd7515 by Andy Soffer <asoffer@google.com>: internal changes PiperOrigin-RevId: 247073879 -- 7bd97e3aad0c3012b89a39392a6ad3f254e9f3c3 by Derek Mauro <dmauro@google.com>: Release commandline flags PiperOrigin-RevId: 247065920 -- 2a991849fd7b140a43b073076d194b61533fd199 by Tom Manshreck <shreck@google.com>: Add documentation for built-in usage flags PiperOrigin-RevId: 247058863 -- 14157b0de45841706bbd631284191fd94c313db9 by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 247058292 -- ed67e0a80468596e30540b367727a250fa415b68 by Abseil Team <absl-team@google.com>: Internal Change. PiperOrigin-RevId: 246828655 -- e1bc8c2aa3f90b3d56c55c5b7244e718c919265d by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 246822325 -- 907a68f287199f749cb9bdb48571b50bc34731e1 by Eric Fiselier <ericwf@google.com>: Accept vector<bool>::reference in StrCat and friends. Converting vector<bool>::reference to alphanum requires two user defined conversions, which isn't allowed. In order to accept this, we need a special constructor that is only enabled for the bool proxy types. PiperOrigin-RevId: 246626732 -- fe4295fa95cc65dee8c881ba12dd8f516e68c40d by Abseil Team <absl-team@google.com>: Clarify the proper way to define AbslHashValue, and fix confusing indentation. PiperOrigin-RevId: 246406528 -- d7174681a72d4a25c8fd2b4d9f515a0763eff87c by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 246358214 -- a7fdc19683cf1a5885e9e1af52fcdb2db1eda53b by Abseil Team <absl-team@google.com>: Fix sample template instantiation. PiperOrigin-RevId: 246354617 -- 29a23c6835f872948d09b24d890385bf195bc995 by Abseil Team <absl-team@google.com>: Fix incorrectly copy-pasted static_assert in absl::optional::value_or The static_assert for a move-constructible type previously said the type must be copy-constructible. PiperOrigin-RevId: 246313827 -- 41884d5872d4ea2c67875b00144b8c8a5859a295 by Greg Falcon <gfalcon@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 245418790 -- 7f90a7f94cdd5e21232c749efe952a750b5c43a2 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 245412658 -- 730a329cf047d54b46971fce1781edd857208c2a by Greg Falcon <gfalcon@google.com>: internal change PiperOrigin-RevId: 245293234 -- cf0216be6338200cbb18167d3f3b2e98e372be77 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 245288164 GitOrigin-RevId: 78293ba4eb4981991ae7e6edd25eb9245fcd7515 Change-Id: I5ea9a852c36c722bae2d6be65fb7f72473d94ab6
2019-05-07 21:56:42 +02:00
}
// Strings and std:: containers do not have the same overload resolution
// considerations as fundamental types. Naming these 'AbslUnparseFlag' means we
// can avoid the need for additional specializations of Unparse (below).
std::string AbslUnparseFlag(absl::string_view v);
std::string AbslUnparseFlag(const std::vector<std::string>&);
template <typename T>
std::string Unparse(const T& v) {
// Comment on next line provides a good compiler error message if T does not
// have UnparseFlag.
return AbslUnparseFlag(v); // Is T missing AbslUnparseFlag?
}
// Overloads for builtin types.
std::string Unparse(bool v);
std::string Unparse(short v); // NOLINT
std::string Unparse(unsigned short v); // NOLINT
std::string Unparse(int v); // NOLINT
std::string Unparse(unsigned int v); // NOLINT
std::string Unparse(long v); // NOLINT
std::string Unparse(unsigned long v); // NOLINT
std::string Unparse(long long v); // NOLINT
std::string Unparse(unsigned long long v); // NOLINT
std::string Unparse(float v);
std::string Unparse(double v);
} // namespace flags_internal
// ParseFlag()
//
// Parses a string value into a flag value of type `T`. Do not add overloads of
// this function for your type directly; instead, add an `AbslParseFlag()`
// free function as documented above.
//
// Some implementations of `AbslParseFlag()` for types which consist of other,
// constituent types which already have Abseil flag support, may need to call
// `absl::ParseFlag()` on those consituent string values. (See above.)
template <typename T>
inline bool ParseFlag(absl::string_view input, T* dst, std::string* error) {
return flags_internal::InvokeParseFlag(input, dst, error);
}
// UnparseFlag()
//
// Unparses a flag value of type `T` into a string value. Do not add overloads
// of this function for your type directly; instead, add an `AbslUnparseFlag()`
// free function as documented above.
//
// Some implementations of `AbslUnparseFlag()` for types which consist of other,
// constituent types which already have Abseil flag support, may want to call
// `absl::UnparseFlag()` on those constituent types. (See above.)
template <typename T>
inline std::string UnparseFlag(const T& v) {
return flags_internal::Unparse(v);
}
} // namespace absl
#endif // ABSL_FLAGS_MARSHALLING_H_